Which one is it ?? Hurry please!!

Answer:

C.

Explanation:

Physicists main field of study is physics. This includes everything from force, matter, energy, and even time among other things. Therefore, from the questions provided the one that would most likely be studied by a physicist would be How can the forces on a space probe be controlled so it will land on Mars? This is because this question deals with forces acting on an object, regardless of what the object is Force is a huge part of physics and therefore studied by Physicists.

Answer:

1. Neutron number = 43

2. Proton number = 34

3. Electron number = 36

Explanation:

From the question given above, the following data were obtained:

Mass number = 77

Charge of ion = –2

1. Determination of the number of neutron.

Mass number of Se = 77

Atomic number = 34

Neutron number =?

NOTE: Atomic number = proton number

Mass number = Proton + Neutron

77 = 34 + Neutron

Collect like terms

77 – 34 = Neutron

Neutron number = 43

2. Determination of the proton number.

The atomic number of an element is simply defined as the number of protons in the atom of the element. Mathematically,

Atomic number = Proton number

Atomic number of Se = 34

Therefore, the proton number of Se²¯ is 34.

NOTE: The atomic number does not change be it atom, ion or molecule. It remains the same.

3. Determination of electron number.

Charge of ion = –2

Proton number = 34

Electron number =?

Proton – Electron = Charge

34 – Electron = –2

Rearrange

34 + 2 = Electron

36 = Electron

Electron number = 36

There are 43 neutrons, 34 protons, and 36 electrons in the given selenium ion with a (-2) charge.

Explanation:

Given:

A selenium ion with a mass number of 77  and a charge of (-2).

To find:

The number of neutrons, protons, and electrons in selenium ion

Solution:

Charge on the selenium  ion = -2

The atomic number of selenium = 34

Number of protons = Atomic number

Number of protons in selenium atom = 34

Number of protons in selenium ion = 34

Number of electrons in selenium atom = 34

Number of electrons in selenium ion=  34+2 = 36

(anion is formed by gaining of electrons that is why adding two electrons )

The mass number of selenium = 77

Mass number = Number of protons + Number of neutrons

77 = 34 + Number of neutrons in selenium

Number of neutrons in selenium ion = 77 - 34 = 43

There are 43 neutrons, 34 protons, and 36 electrons in the given selenium ion with a (-2) charge.

Learn more about atoms and ions here:

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Answer:

i) ciclobutano

ii) 3-etil-4-metil ciclopenteno

Explanation:

Toda la idea de la nomenclatura IUPAC es permitir que la estructura de la sustancia se derive de su nombre y viceversa.

La nomenclatura IUPAC es un sistema universalmente aceptado para nombrar compuestos químicos.

los nombres de los compuestos enumerados son;

i) ciclobutano

ii) 3-etil-4-metil ciclopenteno

Answer:

8.36 g

Explanation:

From;

0.693/t1/2 = 2.303/t log (No/N)

t1/2 = half life of potassium-40

t = age of the sample

No= initial amount of the sample

N= amount of the sample at time t

Substituting values;

0.693/1.3 × 10^9 = 2.303/2.6 × 10^9 log (No/2.10)

5.33 × 10^-10 = 8.86 × 10^-10 log (No/2.10)

5.33 × 10^-10/8.86 × 10^-10 = log (No/2.10)

0.6 = log (No/2.10)

Antilog (0.6) = (No/2.10)

No = 2.10 × Antilog (0.6)

No= 8.36 g

goodnight Gucci chunk cubic DDF if f Ch BK

Answer:

Newton's second law

Explanation:

It is mentioning acceleration and mass

Newton's second law's equation = F = m*a

Hope u understood

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Thank You

Vapourization and condensation. the actual 1 shud be vapourization.

Answer:

I believe it's a.

Explanation:

Answer:

Sodium atoms due to being smaller in size have high ionization energy and thus, it can't lose electrons easily and is more stable and less reactive. ... Hence, from this it is clear that sodium is less reactive than potassium.

Explanation:

Answer:

[tex]{ \bf{PV= \frac{m}{M} RT}} \\ \\ { \tt{(0.65 \times 23.52) = \frac{25}{M} \times 0.081 \times (25 + 273)}} \\ \\ M = 39.5 \: g[/tex]

Answer:

Gain 2, and become negatively charged

Explanation:

A full valence shell, thus stablilized, has 8 electrons, and so it would need two more, and when atoms gain electrons, they become negatively charged because there are now more electrons than protons (and so, when they lose electrons, they become positively charged). Hope this helps! :)

Answer:

B, C, E, G

Explanation:

B - As particles are heated, they gain heat energy (or thermal energy, Q) from whatever the source may be.

C - Thermal energy particles gain is converted into kinetic, and the more KE/kinetic energy particles have, the more energy they have to move around.

E - When particles have more energy to move around more, they slide and move past each other and create more space; hence, they become further apart.

G - Eventually, particles will have enough energy and will move around so much that the attracting forces holding them together in the first place will be lesser than the particle's energy to break free and move from the attractive forces.

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Answer:

I think the answer would be b, sorry if I'm wrong(EDIT: ITS ACTUALLY AAAAA)

Answer:

See explanation

Explanation:

According to the particulate theory of matter, gas particles do not interact with each other. A gas is composed of isolated particles moving at high velocities and collide frequently with each other and the walls of the container.

Since the particles of a gas are mostly isolated, it is easy to compress the gas when pressure is applied thereby bringing the gas particles closer together.

On the other hand, in the solid state, the particles that compose matter are close together. These particles only vibrate about their mean positions due to strong intermolecular interaction between particles. The fact that the particles of the solid ion are so close together makes the solid iron lump to possess high density.

QUËSTIONS :- what are the difference between ionic bond and covalent bond?

IONIC BONDS :- THEY R BONDS WHICH R FORMED DUE TO THE COMPLETE TRANSFER OF ELECTRONS BETWEEN TWO ATOMS

COVALENT BONDS :- THEY R THE BONDS WHICH R FORMED DUE TO INCOMPLETE TRANSFER OF ELECTRONS BETWEEN TWO ATOMS

IONIC BONDS R MORE STRONGER.

Explanation:

Ionic bond is much stronger than covalent bond because it involves complete transfer of electrons because of which there is formation of cation and anion and there exist huge electrostatic forces of attraction. They also have high melting and boiling point which proves that the ionic bond is very strong.

Differences between ionic bond and covalent bond :

Ionic Bonds. Covalent Bonds

Polarity :High. Low

Shape : No definite shape. Definite shape

Melting Point :High Low

Boiling Point: High Low

Answer:

1-Genetics

2-Alleles

3-Organism's genotype

4-Phenotypes and Genotypes

5-Allele

6-Gregor Mendel

7-Genotype

8-Probability

9-Hybrid

10-Genotypic Ratio

11-Phenotypic ratio

12-Heterozygous

Explanation:

Answer:

15/16

Explanation:

We need to find the number of moles of hydrogen and number of moles of ethane present.

Since we have the same mass, m for both substances, the number of moles of hydrogen, n = m/M where M = molar mass of hydrogen molecule

Since hydrogen is H₂, M = 2 × 1 g/mol = 2 × 1 g/mol = 2 mol.

n = m/M

n = m/2

Also, number of moles of ethane, n' = m/M' where M' = molar mass of ethane.

Since ethane is C₂H₆, M' = 2 × 12 g/mol + 6 × 1 g/mol = 24 g/mol + 6 g/mol = 30 g/mol

n' = m/M'

n' = m/30

The total number of moles of gas present is thus n" = n + n' = m/2 + m/30 = (15m + m)/30 = 16m/30

The mole fraction of hydrogen is thus number of moles of hydrogen/total number of moles = n/n" = m/2 ÷ 16m/30 = m/2 × 30/16m = 15/16

Also, since the partial pressure due to hydrogen, P = mole fraction × total pressure, P'

P/P' = mole fraction = 15/16

So, The fraction of the total pressure exerted by hydrogen is 15/16

Answer:

fecl2+ h2

Explanation:

Answer:

Therefore, 2 moles of oxygen will be required to oxidize 2.66 moles of oxygen. 72g of Aluminium will be completely oxidized by 44.8 lit of oxygen at STP.

Answer:

24cm

Explanation:

The perimeter of a polygon is obtained by the sum of the length of each side of the figure.

The polygon of the problem has four sides with the following measurements:

8cm, 6cm, 4cm and 6cm.

That means the perimeter of this shape is:

8cm + 6cm + 4cm + 6cm =

Answer:

Emulsion

Explanation:

According to Oxford dictionary, a colloid is, ''a homogeneous non-crystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance. Colloids include gels, sols, and emulsions; the particles do not settle, and cannot be separated out by ordinary filtering or centrifuging like those in a suspension.''

An emulsion is a dispersion of a liquid in a liquid. This means that the the physical state of dispersed phase and dispersion medium is same.

Examples of emulsions include; Vinaigrette, homogenized milk and hair cream.

Answer:

Calcium= 2,8,8,2

Potassium= 2,8,8,1

Answer:

Atomic number of potassium = 19

Therefore number of electrons = 19

Since, maximum number of electrons in outermost orbit will not be more than 8, thus the 19th electron of potassium atom will reside in 4th.

Thus, electronic configuration of potassium is

given in first pic.

Number of orbit in potassium = 4

Atomic number of calcium = 20

Therefore number of electrons = 20

Thus, electronic configuration of calcium is given in sec pic.

Number of orbit in calcium = 4

Explanation:

#keep learning!!

Answer:

c. nilai pH kurang dari 7

Explanation:

cuka adalah acid

nilai pH bagi acid adalah

antara 1 hingga 6

Answer:

The amount is $282953.72 using the given formula

Answer:

catalyst

Explanation:

it alters the speed of reaction

Answer:

Coke

Explanation:

A solid fuel formed by heating coal in the absence of air is coke. Coke is black colored, tough porous substance. It is pure carbon.

Answer:

Generally SN1 reactions are carried out in polar protic solvents. The energy required for breaking the C-X bond is obtained through solvation of halide ion with the proton of the solvent. Tertiary alkyl halides undergo SN1 reaction very fast because of the high stability of tertiary carbocations.